ET WEB_SPECIFIC_APPS ASUS GT-AC2900 Authentication Bypass via Null Character in asus_token HTTP Cookie (CVE-2021-32030)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS ASUS GT-AC2900 Authentication Bypass via Null Character in asus_token HTTP Cookie (CVE-2021-32030)";
    flow:established,to_server;
    http.uri;
    content:"/appGet.cgi|3f|"; startswith;
    content:"hook|3d|get_cfg_clientlist|28 29|"; fast_pattern;
    http.cookie;
    content:"asus_token|3d|";
    pcre:"/^(?:\x00|\x2500|\x5c0)/R";
    reference:url,www.atredis.com/blog/2021/4/30/asus-authentication-bypass;
    reference:cve,2021-32030;
    classtype:web-application-attack;
    sid:2064924; rev:1;
    metadata:affected_product Asus, created_at 2025_09_25, cve CVE_2021_32030, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_25, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)